The Claim

In trained males and females, resistance training with matched load and time under load produces similar increases in muscular strength regardless of repetition duration, whether performed at 2s:4s, 10s:10s, or 30s:30s:30s, indicating that the speed of movement is not a critical determinant of strength gains when effort is maximized to momentary failure.

Source: Neither repetition duration nor number of muscle actions affect strength increases, body composition, muscle size, or fasted blood glucose in trained males and females.

What the research says

Supports is higher

Support is ahead, but a single strong opposing study can change this.

Supports
69score
Challenges
0score

These are independent scores, not a percentage. Higher-grade studies count more, so a single strong opposing study can outweigh several weaker ones.

Cause and effect
1 study reviewed
In plain English

When trained individuals lift weights with the same total load and time under tension, their strength gains are the same whether they lift slowly or quickly, as long as they push to complete muscular failure.

See the scientific wording

In trained males and females, resistance training with matched load and time under load produces similar increases in muscular strength regardless of repetition duration, whether performed at 2s:4s, 10s:10s, or 30s:30s:30s, indicating that the speed of movement is not a critical determinant of strength gains when effort is maximized to momentary failure.

Why this might work

When muscles are pushed until they can't move the weight anymore, all muscle fibers are activated, no matter how fast or slow the movement is. This full activation trains the nervous system to fire more strongly and coordinate better, making the muscle stronger over time.

Verified mechanismbased on 1 study

What the research says

1 study
  1. Study: Neither repetition duration nor number of muscle actions affect strength increases, body composition, muscle size, or fasted blood glucose in trained males and females.

    When people who already lift weights train with the same weight and total time, it doesn’t matter if they lift slowly or quickly—they get just as stronger either way, as long as they push until they can’t do another rep.

Score breakdown, mechanism chain, raw evidence, ideal studies needed & 1 supporting studies

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Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.